US20120181234A1 - Filter and method for filtration of hydraulic oil in a return line to a hydraulic tank, and a drilling rig comprising the filter - Google Patents
Filter and method for filtration of hydraulic oil in a return line to a hydraulic tank, and a drilling rig comprising the filter Download PDFInfo
- Publication number
- US20120181234A1 US20120181234A1 US13/261,246 US201013261246A US2012181234A1 US 20120181234 A1 US20120181234 A1 US 20120181234A1 US 201013261246 A US201013261246 A US 201013261246A US 2012181234 A1 US2012181234 A1 US 2012181234A1
- Authority
- US
- United States
- Prior art keywords
- filter
- hydraulic
- oil
- arrangement
- level
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000010720 hydraulic oil Substances 0.000 title claims abstract description 44
- 238000005553 drilling Methods 0.000 title claims description 19
- 238000001914 filtration Methods 0.000 title claims description 14
- 238000000034 method Methods 0.000 title claims description 4
- 239000003921 oil Substances 0.000 claims abstract description 44
- 239000002245 particle Substances 0.000 description 8
- 238000005516 engineering process Methods 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 210000002445 nipple Anatomy 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/11—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements
- B01D29/114—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements arranged for inward flow filtration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/11—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements
- B01D29/114—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements arranged for inward flow filtration
- B01D29/115—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements arranged for inward flow filtration open-ended, the arrival of the mixture to be filtered and the discharge of the concentrated mixture are situated on both opposite sides of the filtering element
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/60—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor integrally combined with devices for controlling the filtration
- B01D29/605—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor integrally combined with devices for controlling the filtration by level measuring
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
- B01D35/02—Filters adapted for location in special places, e.g. pipe-lines, pumps, stop-cocks
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
- B01D35/14—Safety devices specially adapted for filtration; Devices for indicating clogging
- B01D35/143—Filter condition indicators
- B01D35/1435—Filter condition indicators with alarm means
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
- B01D35/14—Safety devices specially adapted for filtration; Devices for indicating clogging
- B01D35/147—Bypass or safety valves
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B4/00—Drives for drilling, used in the borehole
- E21B4/02—Fluid rotary type drives
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2201/00—Details relating to filtering apparatus
- B01D2201/48—Overflow systems
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
- F15B21/04—Special measures taken in connection with the properties of the fluid
- F15B21/041—Removal or measurement of solid or liquid contamination, e.g. filtering
Definitions
- the present invention relates to a filter according to the introduction to claim 1 .
- hydraulic oil is returned in return lines to a hydraulic tank.
- Hydraulic oil from most of the hydraulic components in the hydraulic system passes through a return filter on its way back to the hydraulic tank.
- This filter is often of a type that has a pressure-based bypass function.
- a number of hydraulic components require separate return lines of internally leaking hydraulic oil directly to the hydraulic tank, without passing a return filter, since the return line must be “free of pressure”, i.e. it must have normal atmospheric pressure without any significant back pressure. It would be possible, otherwise, for such back pressure from, for example, a filter to change the function of, for example, a valve or to cause failure of a hydraulic pump.
- the hydraulic pump in particular, is very sensitive to back pressure, since the housing of the pump with its bearings, pistons, etc. will be placed under pressure. An increased housing pressure influences the pistons such that they loose contact with the sliding plate of the hydraulic pump, thus causing pump failure.
- the limit for the back pressure that the manufacturers allow may lie at approximately 0.5-2 bar above the pressure that is present in the suction line of the hydraulic pump, but the manufacturers prefer the pressure to be lower than this and for this reason advise against the installation of return filters.
- the return line of a variable hydraulic pump must be dimensioned taking into consideration the small volume of oil that the adjusting piston presses out into the return line in the short period (25-100 ms) during which the hydraulic pump changes the displacement.
- the volume of oil removed in the return line thus corresponds to a large value of the flow, specified in litre/min.
- the prior art technology for avoiding back pressure in the return lines for the hydraulic components that are sensitive to back pressure is solely the direct routing of the return lines from the said hydraulic components and the leakage connections to the hydraulic tank and its leakage connections, without passing the return filter of the hydraulic tank.
- a filter is presented with the characteristics specified in claim 1 .
- the advantage is that filtration is carried out without the filter causing any significant back pressure, not even in the event of temporarily high leakage flows of hydraulic oil, since a level-based bypass function can be used in the filter.
- the filter can thus be used for hydraulic components that are sensitive to back pressure.
- the invention would, for example, in the event of bearings failure in a hydraulic pump capture the particles from the failure that have been transported from the leakage line of the hydraulic pump in to the hydraulic tank.
- FIG. 1 shows an overview of a prior art hydraulic system in a drilling rig
- FIG. 2 shows an overview of a hydraulic system in a drilling rig according to the invention
- FIG. 3 shows a cross-section of a filter according to one embodiment.
- FIG. 1 shows an overview of a prior art hydraulic system 1 comprising a number of different hydraulic components in a drilling rig with at least one drilling machine.
- the hydraulic system 1 is connected to a hydraulic tank 2 .
- One or several hydraulic pumps 3 pump hydraulic oil through one or several suction oil lines S from the hydraulic tank 2 to the hydraulic pump 3 and through one or several pressurised lines P from the hydraulic pump 3 to the hydraulic system 1 .
- Most of the hydraulic oil then returns through one or several first return lines T 1 , T 2 from the hydraulic system 1 to a first return filter 4 and from the first return filter 4 to the hydraulic tank 2 .
- the first return filter 4 may be of a conventional type with a pressure-based bypass function 6 , which means that the oil in the first return lines T 1 , T 2 is led past the first return filter 4 if the pressure in the first return filter 4 becomes too high.
- Certain hydraulic components are sensitive to the back pressure that a conventional return filter 4 with a pressure-based bypass function 6 can cause. This is particularly the case for a drilling rig, in which what is known as a full-flow filter is often used as return filter 4 , while at the same time the return flow of hydraulic oil can be 200-600 l/min, which is the reason that a relatively high back pressure may be created.
- the hydraulic components 3 that are sensitive to back pressure therefore, have a return flow connected directly to the hydraulic tank 2 through second return lines L 1 , L 2 , without a conventional return filter 4 . It is most often a case of leakage oil flows.
- FIG. 2 shows an overview of a hydraulic system in a drilling rig according to the invention where one or several second return filters 5 are arranged for the second return lines L 1 , L 2 and with one or several additional second return lines L 3 between the second return filter 5 and the hydraulic tank 2 .
- the second return filter 5 has a level-based bypass function that will be described in more detail below using an embodiment.
- the second return filter 5 may be integrated into the hydraulic tank 2 or it may be separate from the hydraulic tank 2 .
- FIG. 3 shows an embodiment of the second return filter 5 .
- the second return filter 5 comprises a filter holder 11 , one or several filter elements 12 , one or several inlets 13 in to the filter holder 11 , one or several outlets 14 from the filter holder 11 and one or several openings 15 .
- the filter element 12 is arranged for the filtering of oil between the inlet 13 and the outlet 14 .
- the opening 15 is arranged as a filter-free passage between the inlet 13 and the outlet 14 .
- the filter element 12 may have any one of several appearances.
- the most simple model of the filter element 12 may be a straight wall between the inlet 13 and the outlet 14 with an opening 15 in the form of an open area above it.
- the greatest advantage, however, is obtained with a filter element 12 that has the form of a cylinder, since this has the greatest filtration area. It is advantageous to have a wavy edge of the filter element 12 , in order to further increase this filtration area.
- the filter element 12 should be sufficiently finely masked to capture as many particles as possible, but not so finely masked that the flow through the filter element 12 becomes too slow.
- a suitable grade for the filter is, for example, 100 ⁇ m absolute.
- FIG. 3 shows that the inlet 13 to the second return filter 5 is arranged on the outer surface of a filter element 12 with the form of a cylinder, while the outlet 14 is arranged on the inner surface of the filter element 12 for filtration from the outside inwards, but it is equally possible to exchange the locations of the inlet 13 and the outlet 14 , such that filtration occurs instead from the inside outwards.
- Hydraulic oil from the return lines L 1 , L 2 of the hydraulic components that are sensitive to back pressure is led into the filter holder 11 through the inlet 13 of the filter holder.
- the hydraulic oil does not normally arrive at a steady rate of flow: it can vary wildly over time.
- an oil level H of the unfiltered hydraulic oil 16 rises.
- the filter element 13 allows the passage of an amount of hydraulic oil 17 and filters this amount, which is led out from the filter holder 11 through its outlet 14 and return lines L 3 to the hydraulic tank 2 .
- the ratio between the inflow of unfiltered hydraulic oil 16 into the filter holder 11 and the outflow of filtered hydraulic oil 17 from the filter holder 11 determines the volume of the unfiltered hydraulic oil 16 and thus the level H. If the inflow increases rapidly relative to the outflow, as may occur, for example, following a sudden change in the displacement of the hydraulic pump 3 , the oil level H rises and the volume of free air 18 above the hydraulic oil 16 , 17 is reduced.
- the filter construction accumulates the short-term increases in volume in the filter holder 11 and carries out full filtration without creating any significant back pressure in the leakage lines L 1 , L 2 .
- Full filtration is achieved as long as the increasing inflow creates an oil level H that is lower than a first level H 1 , which corresponds to the height of the filter element 12 to the opening 15 . If the inflow increases further, the excess incoming unfiltered hydraulic oil 16 is led through the opening 15 of the filter element and onwards through the outlet 14 of the filter holder 11 to the hydraulic tank 2 , without being filtered and without creating any significant back pressure.
- a filter 5 with a level-based bypass function has in this case been achieved, instead of a conventional pressure-based bypass function.
- the filter holder 11 be transparent, such that it is easy to see what is happening inside the filter. It is even more advantageous to install a level sensor 19 , for example an electrical level sensor, in order to measure the oil level H. If the oil level H in the filter holder exceeds the first level H 1 , which is the limit for full filtration, the system can carry out at least one of raising an alarm and switching off necessary components, which for a drilling machine probably is the complete drilling machine. This is to avoid unfiltered hydraulic oil 16 from the second return lines L 1 , L 2 returning to the hydraulic tank 2 . The alarm may in this case be an indication that the filter must be exchanged or cleaned.
- a level sensor 19 for example an electrical level sensor
- the oil level H continues to rise above the first level H 1 and the opening 15 is not sufficient to deal with the inflow of unfiltered oil 16 , there is a risk that the oil level H will rise to a second level H 2 , which in FIG. 3 corresponds to the ceiling 20 of the filter holder.
- a pressure will in this case build up in the filter holder 11 , which pressure will create an undesired back pressure in the leakage lines L 1 , L 2 , which risks destroying hydraulic components.
- the level sensor 19 can in this case raise an alarm and switch off necessary components.
- a further alternative may be only to raise an alarm at the first level H 1 , while both raising the alarm and switching off take place at the second level H 2 in order to avoid back pressure in the leakage lines L 1 , L 2 .
- a variant of the first alternative can be to keep the opening 15 normally closed, and to open it when the level sensor 19 raises an alarm. It may be advantageous to use the most recent alternative in an environment in which the filter is, for example, exposed to much shaking, and there is otherwise a risk that unfiltered oil will splash into the opening 15 .
- the inlet 13 is instead positioned on the inner surface of the filter element 12 —for filtration from the inside outwards—or if the inlet 13 is, for example, located in the ceiling 20 or the wall 23 of the filter holder.
- the air 18 in the filter holder 11 influences the outflow of hydraulic oil 17 from the filter holder 11 . Since the amount of hydraulic oil 16 , 17 in the filter holder 11 can vary in an undesired manner, the air pressure will be affected if the filter holder 11 is hermetically sealed. The air pressure will, for example, fall if more hydraulic oil flows out from the filter holder 11 than flows in to the filter holder 11 , and it is therefore possible for hydraulic oil 16 , 17 to be trapped inside the filter holder 11 . In order to avoid large changes in air pressure, the air 18 can be placed in contact with, for example, the air in the hydraulic tank 2 through, for example, a nipple 24 .
- the small back pressure that arises from the return filter 5 is principally caused by two factors: the oil level H in the filter holder 11 and the air pressure in the air 18 above the oil.
- the oil level H in the filter holder 11 is sufficient in a drilling rig to have a first level H of approximately 133 mm, which would give a back pressure of approximately 0.01 bar from the oil level. This is negligible in this context.
- the air pressure can give a maximum back pressure of 0.2 bar, which would have arisen also if the return lines L 1 , L 2 had been connected directly to the hydraulic tank 2 according to prior art technology and which lies far below the limit of 0.5 bar set by the manufacturers.
- the second return filter 5 is used for leakage oil from, for example, hydraulic pumps 3 . It is, however, naturally possible to use the second return filter 5 for any return oil at all—including return oil from hydraulic components that can withstand back pressure: it is simply necessary to dimension the return filter 5 accordingly. It is possible also not to use a first return filter 4 , and allow the second return filter 5 to deal with all return oil.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Geochemistry & Mineralogy (AREA)
- Analytical Chemistry (AREA)
- General Engineering & Computer Science (AREA)
- Fluid-Pressure Circuits (AREA)
- Filtration Of Liquid (AREA)
- Supply Devices, Intensifiers, Converters, And Telemotors (AREA)
Abstract
Description
- The present invention relates to a filter according to the introduction to claim 1.
- In a hydraulic system, such as a drilling rig, hydraulic oil is returned in return lines to a hydraulic tank. Hydraulic oil from most of the hydraulic components in the hydraulic system passes through a return filter on its way back to the hydraulic tank. This filter is often of a type that has a pressure-based bypass function.
- A number of hydraulic components, however, require separate return lines of internally leaking hydraulic oil directly to the hydraulic tank, without passing a return filter, since the return line must be “free of pressure”, i.e. it must have normal atmospheric pressure without any significant back pressure. It would be possible, otherwise, for such back pressure from, for example, a filter to change the function of, for example, a valve or to cause failure of a hydraulic pump. The hydraulic pump, in particular, is very sensitive to back pressure, since the housing of the pump with its bearings, pistons, etc. will be placed under pressure. An increased housing pressure influences the pistons such that they loose contact with the sliding plate of the hydraulic pump, thus causing pump failure. The limit for the back pressure that the manufacturers allow may lie at approximately 0.5-2 bar above the pressure that is present in the suction line of the hydraulic pump, but the manufacturers prefer the pressure to be lower than this and for this reason advise against the installation of return filters.
- The return line of a variable hydraulic pump must be dimensioned taking into consideration the small volume of oil that the adjusting piston presses out into the return line in the short period (25-100 ms) during which the hydraulic pump changes the displacement. The volume of oil removed in the return line thus corresponds to a large value of the flow, specified in litre/min.
- The prior art technology for avoiding back pressure in the return lines for the hydraulic components that are sensitive to back pressure is solely the direct routing of the return lines from the said hydraulic components and the leakage connections to the hydraulic tank and its leakage connections, without passing the return filter of the hydraulic tank.
- One problem when using the prior art technology is that the hydraulic oil from the hydraulic components that are sensitive to back pressure does not pass through a return filter, and thus the hydraulic oil is not filtered. This means, among other things, that particles from, for example, the slide bearings and roller bearings of the hydraulic pump pass directly to the hydraulic tank without being filtered out. The particles then accompany the hydraulic oil back into the hydraulic system and to the hydraulic components that constitute it, and generate further particles through wear, leading to disturbance of function and abnormal wear. The cleaning of the hydraulic system that is required after pump failure is extensive. It is difficult also to obtain complete elimination of the particles that have been distributed throughout the hydraulic system without exchanging the hydraulic component involved. Remaining particles will, in the worst case, cause problems in the hydraulic system in the future.
- According to one aspect of the invention, a filter is presented with the characteristics specified in
claim 1. - The advantage is that filtration is carried out without the filter causing any significant back pressure, not even in the event of temporarily high leakage flows of hydraulic oil, since a level-based bypass function can be used in the filter. The filter can thus be used for hydraulic components that are sensitive to back pressure. The invention would, for example, in the event of bearings failure in a hydraulic pump capture the particles from the failure that have been transported from the leakage line of the hydraulic pump in to the hydraulic tank.
- It would otherwise be possible for these particles to be sucked into the hydraulic pump and in this way further damage it, and to be distributed again through the hydraulic system and damage other hydraulic components. The collateral damage following pump failure, and thus also the extent of the cleaning of the hydraulic system required, are minimised through the invention.
- The invention will be described in more detail with the aid of a preferred embodiment and with reference to the attached drawings, of which
-
FIG. 1 shows an overview of a prior art hydraulic system in a drilling rig, -
FIG. 2 shows an overview of a hydraulic system in a drilling rig according to the invention, and -
FIG. 3 shows a cross-section of a filter according to one embodiment. -
FIG. 1 shows an overview of a prior arthydraulic system 1 comprising a number of different hydraulic components in a drilling rig with at least one drilling machine. Thehydraulic system 1 is connected to ahydraulic tank 2. One or severalhydraulic pumps 3 pump hydraulic oil through one or several suction oil lines S from thehydraulic tank 2 to thehydraulic pump 3 and through one or several pressurised lines P from thehydraulic pump 3 to thehydraulic system 1. Most of the hydraulic oil then returns through one or several first return lines T1, T2 from thehydraulic system 1 to afirst return filter 4 and from thefirst return filter 4 to thehydraulic tank 2. Thefirst return filter 4 may be of a conventional type with a pressure-basedbypass function 6, which means that the oil in the first return lines T1, T2 is led past thefirst return filter 4 if the pressure in thefirst return filter 4 becomes too high. - Certain hydraulic components, in particular
hydraulic pumps 3, are sensitive to the back pressure that aconventional return filter 4 with a pressure-basedbypass function 6 can cause. This is particularly the case for a drilling rig, in which what is known as a full-flow filter is often used asreturn filter 4, while at the same time the return flow of hydraulic oil can be 200-600 l/min, which is the reason that a relatively high back pressure may be created. Thehydraulic components 3 that are sensitive to back pressure, therefore, have a return flow connected directly to thehydraulic tank 2 through second return lines L1, L2, without aconventional return filter 4. It is most often a case of leakage oil flows. -
FIG. 2 shows an overview of a hydraulic system in a drilling rig according to the invention where one or severalsecond return filters 5 are arranged for the second return lines L1, L2 and with one or several additional second return lines L3 between thesecond return filter 5 and thehydraulic tank 2. Thesecond return filter 5 has a level-based bypass function that will be described in more detail below using an embodiment. In practice, thesecond return filter 5 may be integrated into thehydraulic tank 2 or it may be separate from thehydraulic tank 2. -
FIG. 3 shows an embodiment of thesecond return filter 5. Thesecond return filter 5 comprises a filter holder 11, one orseveral filter elements 12, one orseveral inlets 13 in to the filter holder 11, one orseveral outlets 14 from the filter holder 11 and one orseveral openings 15. Thefilter element 12 is arranged for the filtering of oil between theinlet 13 and theoutlet 14. The opening 15 is arranged as a filter-free passage between theinlet 13 and theoutlet 14. - The
filter element 12 may have any one of several appearances. The most simple model of thefilter element 12 may be a straight wall between theinlet 13 and theoutlet 14 with anopening 15 in the form of an open area above it. The greatest advantage, however, is obtained with afilter element 12 that has the form of a cylinder, since this has the greatest filtration area. It is advantageous to have a wavy edge of thefilter element 12, in order to further increase this filtration area. Thefilter element 12 should be sufficiently finely masked to capture as many particles as possible, but not so finely masked that the flow through thefilter element 12 becomes too slow. A suitable grade for the filter is, for example, 100 μm absolute. -
FIG. 3 shows that theinlet 13 to thesecond return filter 5 is arranged on the outer surface of afilter element 12 with the form of a cylinder, while theoutlet 14 is arranged on the inner surface of thefilter element 12 for filtration from the outside inwards, but it is equally possible to exchange the locations of theinlet 13 and theoutlet 14, such that filtration occurs instead from the inside outwards. - Hydraulic oil from the return lines L1, L2 of the hydraulic components that are sensitive to back pressure is led into the filter holder 11 through the
inlet 13 of the filter holder. The hydraulic oil does not normally arrive at a steady rate of flow: it can vary wildly over time. When an addition is made to the volume of oil of the filter holder 11 with its unfilteredhydraulic oil 16, an oil level H of the unfilteredhydraulic oil 16 rises. At the same time, thefilter element 13 allows the passage of an amount of hydraulic oil 17 and filters this amount, which is led out from the filter holder 11 through itsoutlet 14 and return lines L3 to thehydraulic tank 2. - The ratio between the inflow of unfiltered
hydraulic oil 16 into the filter holder 11 and the outflow of filtered hydraulic oil 17 from the filter holder 11 determines the volume of the unfilteredhydraulic oil 16 and thus the level H. If the inflow increases rapidly relative to the outflow, as may occur, for example, following a sudden change in the displacement of thehydraulic pump 3, the oil level H rises and the volume offree air 18 above thehydraulic oil 16, 17 is reduced. The filter construction accumulates the short-term increases in volume in the filter holder 11 and carries out full filtration without creating any significant back pressure in the leakage lines L1, L2. - Full filtration is achieved as long as the increasing inflow creates an oil level H that is lower than a first level H1, which corresponds to the height of the
filter element 12 to theopening 15. If the inflow increases further, the excess incoming unfilteredhydraulic oil 16 is led through theopening 15 of the filter element and onwards through theoutlet 14 of the filter holder 11 to thehydraulic tank 2, without being filtered and without creating any significant back pressure. Afilter 5 with a level-based bypass function has in this case been achieved, instead of a conventional pressure-based bypass function. - It is an advantage that the filter holder 11 be transparent, such that it is easy to see what is happening inside the filter. It is even more advantageous to install a
level sensor 19, for example an electrical level sensor, in order to measure the oil level H. If the oil level H in the filter holder exceeds the first level H1, which is the limit for full filtration, the system can carry out at least one of raising an alarm and switching off necessary components, which for a drilling machine probably is the complete drilling machine. This is to avoid unfilteredhydraulic oil 16 from the second return lines L1, L2 returning to thehydraulic tank 2. The alarm may in this case be an indication that the filter must be exchanged or cleaned. - If the oil level H continues to rise above the first level H1 and the
opening 15 is not sufficient to deal with the inflow ofunfiltered oil 16, there is a risk that the oil level H will rise to a second level H2, which inFIG. 3 corresponds to theceiling 20 of the filter holder. A pressure will in this case build up in the filter holder 11, which pressure will create an undesired back pressure in the leakage lines L1, L2, which risks destroying hydraulic components. Thelevel sensor 19 can in this case raise an alarm and switch off necessary components. - Thus, it may be an alternative to raise an alarm and switch off already at the first level H1 in order to prevent any significant amount of
unfiltered oil 16 from passing the filter. A further alternative may be only to raise an alarm at the first level H1, while both raising the alarm and switching off take place at the second level H2 in order to avoid back pressure in the leakage lines L1, L2. A variant of the first alternative can be to keep theopening 15 normally closed, and to open it when thelevel sensor 19 raises an alarm. It may be advantageous to use the most recent alternative in an environment in which the filter is, for example, exposed to much shaking, and there is otherwise a risk that unfiltered oil will splash into theopening 15. - If a large inflow of unfiltered
hydraulic oil 16 occurs suddenly and theinlet 13 is located in the floor of the filter holder, the unfilteredhydraulic oil 16 may splash up onto theceiling 20 of the filter holder, even though the filter holder 11 is not full, and in this way possibly cause a false alarm for too high a level H1, H2. Alternatively, or in addition to this, an amount of unfilteredhydraulic oil 16 may splash out through theopening 15. It may for this reason be advantageous with anobstacle 22 at theinlet 13 that ensures that the unfilteredhydraulic oil 16 is forced to take a slight deviation and thus behave more calmly. It is, of course, possible to arrangecorresponding obstacles 22 as inFIG. 3 at theinlet 13, if theinlet 13 is instead positioned on the inner surface of thefilter element 12—for filtration from the inside outwards—or if theinlet 13 is, for example, located in theceiling 20 or thewall 23 of the filter holder. - The
air 18 in the filter holder 11 influences the outflow of hydraulic oil 17 from the filter holder 11. Since the amount ofhydraulic oil 16, 17 in the filter holder 11 can vary in an undesired manner, the air pressure will be affected if the filter holder 11 is hermetically sealed. The air pressure will, for example, fall if more hydraulic oil flows out from the filter holder 11 than flows in to the filter holder 11, and it is therefore possible forhydraulic oil 16, 17 to be trapped inside the filter holder 11. In order to avoid large changes in air pressure, theair 18 can be placed in contact with, for example, the air in thehydraulic tank 2 through, for example, anipple 24. The same air pressure is then obtained in the filter holder 11 as in thehydraulic tank 2, which today lies at a pressure 0-0.2 bar above atmospheric pressure. This leads to improved flow between thesecond return filter 5 and thehydraulic tank 2. It is possible, naturally, to equalise the pressure using other methods. - The small back pressure that arises from the
return filter 5 is principally caused by two factors: the oil level H in the filter holder 11 and the air pressure in theair 18 above the oil. Experiments have shown that it is sufficient in a drilling rig to have a first level H of approximately 133 mm, which would give a back pressure of approximately 0.01 bar from the oil level. This is negligible in this context. As has been mentioned above, the air pressure can give a maximum back pressure of 0.2 bar, which would have arisen also if the return lines L1, L2 had been connected directly to thehydraulic tank 2 according to prior art technology and which lies far below the limit of 0.5 bar set by the manufacturers. - It has been described above principally how the
second return filter 5 is used for leakage oil from, for example, hydraulic pumps 3. It is, however, naturally possible to use thesecond return filter 5 for any return oil at all—including return oil from hydraulic components that can withstand back pressure: it is simply necessary to dimension thereturn filter 5 accordingly. It is possible also not to use afirst return filter 4, and allow thesecond return filter 5 to deal with all return oil. - The invention is, naturally, not limited to the example described above: it can be modified within the scope of the attached patent claims.
Claims (20)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE0950893-8 | 2009-11-24 | ||
SE0950893A SE534326C2 (en) | 2009-11-24 | 2009-11-24 | Filter and method for filtering hydraulic oil in a return line to a hydraulic tank, and a drilling rig comprising the filter |
PCT/SE2010/051192 WO2011065891A1 (en) | 2009-11-24 | 2010-11-03 | Filter and method for filtration of hydraulic oil in a return line to a hydraulic tank, and a drilling rig comprising the filter |
Publications (2)
Publication Number | Publication Date |
---|---|
US20120181234A1 true US20120181234A1 (en) | 2012-07-19 |
US9776110B2 US9776110B2 (en) | 2017-10-03 |
Family
ID=44066778
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/261,246 Expired - Fee Related US9776110B2 (en) | 2009-11-24 | 2010-11-03 | Filter and method for filtration of hydraulic oil in a return line to a hydraulic tank, and a drilling rig comprising the filter |
Country Status (5)
Country | Link |
---|---|
US (1) | US9776110B2 (en) |
EP (1) | EP2504076A4 (en) |
CN (1) | CN102665853B (en) |
SE (1) | SE534326C2 (en) |
WO (1) | WO2011065891A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10350521B2 (en) | 2013-01-15 | 2019-07-16 | United Technologies Corporation | Fuel system ice and debris separator (IDS) with partial filter screen and torturous path |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112746994B (en) * | 2020-12-31 | 2023-05-26 | 航天重型工程装备有限公司 | Liquid returning box, hydraulic oil tank and hydraulic system |
CN113713453B (en) * | 2021-08-13 | 2022-11-11 | 国网江苏省电力有限公司南通供电分公司 | Filtering control equipment for transformer oil and control method thereof |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2707562A (en) * | 1952-04-17 | 1955-05-03 | Bendix Aviat Corp | Filter |
US2998138A (en) * | 1959-02-24 | 1961-08-29 | Aero Supply Mfg Company | Filter bypass indicator |
US3525404A (en) * | 1968-02-23 | 1970-08-25 | Hughes Tool Co | Rotary drilling rig with direct power drive and simplified controls |
US3750888A (en) * | 1971-09-13 | 1973-08-07 | Caterpillar Tractor Co | Filter assembly |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB735368A (en) | 1952-04-17 | 1955-08-17 | Bendix Aviat Corp | Filter |
DE2036302C3 (en) * | 1970-07-22 | 1981-07-23 | Purolator Filter GmbH, 7110 Öhringen | Filter arrangement, in particular for oil return filters in motor vehicles |
DE2429510A1 (en) | 1974-06-20 | 1976-01-02 | Brichta Werner | Bypass valve for hydraulic oil filter - being piston valve which opens recycle when pressure drop exceeds set valve |
DE3400820A1 (en) * | 1984-01-12 | 1985-07-18 | Johannes 2050 Hamburg Donat | Monitoring device for monitoring the pressure-relief valve in non-reusable and disposable filters |
DE69509514T2 (en) | 1995-02-22 | 1999-10-28 | Parker Hannifin Oy, Urjala As | FILTER PROVIDED BY A BYPASS OPENING |
DE19515962A1 (en) | 1995-03-29 | 1996-10-02 | Argo Gmbh Fuer Fluidtechnik | Hydraulic circuit |
US7243740B2 (en) * | 2003-12-05 | 2007-07-17 | Pathfinder Energy Services, Inc. | Filter assembly having a bypass passageway and method |
JP2005288391A (en) * | 2004-04-02 | 2005-10-20 | Hitachi Ltd | Oil filter device |
BRPI0722165A2 (en) | 2007-10-19 | 2014-03-18 | Mp Filtri S P A | PRESSURE OIL FILTERING DEVICE |
-
2009
- 2009-11-24 SE SE0950893A patent/SE534326C2/en not_active IP Right Cessation
-
2010
- 2010-11-03 US US13/261,246 patent/US9776110B2/en not_active Expired - Fee Related
- 2010-11-03 WO PCT/SE2010/051192 patent/WO2011065891A1/en active Application Filing
- 2010-11-03 CN CN201080052835.1A patent/CN102665853B/en not_active Expired - Fee Related
- 2010-11-03 EP EP10833657.9A patent/EP2504076A4/en not_active Withdrawn
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2707562A (en) * | 1952-04-17 | 1955-05-03 | Bendix Aviat Corp | Filter |
US2998138A (en) * | 1959-02-24 | 1961-08-29 | Aero Supply Mfg Company | Filter bypass indicator |
US3525404A (en) * | 1968-02-23 | 1970-08-25 | Hughes Tool Co | Rotary drilling rig with direct power drive and simplified controls |
US3750888A (en) * | 1971-09-13 | 1973-08-07 | Caterpillar Tractor Co | Filter assembly |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10350521B2 (en) | 2013-01-15 | 2019-07-16 | United Technologies Corporation | Fuel system ice and debris separator (IDS) with partial filter screen and torturous path |
Also Published As
Publication number | Publication date |
---|---|
CN102665853B (en) | 2015-04-15 |
EP2504076A1 (en) | 2012-10-03 |
SE0950893A1 (en) | 2011-05-25 |
CN102665853A (en) | 2012-09-12 |
SE534326C2 (en) | 2011-07-12 |
EP2504076A4 (en) | 2013-07-03 |
WO2011065891A1 (en) | 2011-06-03 |
US9776110B2 (en) | 2017-10-03 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5736352B2 (en) | Oil filter device | |
EP2055364A2 (en) | A suction filter for an automatic transmission | |
US6932902B2 (en) | Hydraulic oil filtration apparatus | |
US6953019B2 (en) | Oil Filter assembly for an internal combustion engine | |
US9776110B2 (en) | Filter and method for filtration of hydraulic oil in a return line to a hydraulic tank, and a drilling rig comprising the filter | |
JP7387016B2 (en) | mission oil filter module | |
US4322290A (en) | Filter assembly | |
JP2019528156A (en) | Filtration system for oil filtration for marine machinery such as ship engines | |
CN102648034B (en) | Pressure filter device | |
US3053389A (en) | Oil filters | |
US6637551B2 (en) | Check ball filter for transmissions | |
US6599229B1 (en) | Air-assisted drain with pressure cutoff valve | |
JPH0719538Y2 (en) | Full flow filter | |
KR0139661Y1 (en) | An induction pipe mounting structure for emergency supply in oil tank | |
JP2008126204A (en) | Filter device, filter monitor, and construction machine | |
KR200223973Y1 (en) | Means of suction diffuser and strainer | |
JP2019529801A (en) | Screw compressor for commercial vehicles | |
KR100976785B1 (en) | Drain line for swash plate type compressor | |
EP3684493B1 (en) | Internal continuous air bypass | |
CN212643027U (en) | Automatic exhaust device for pump room water pump | |
US20040141854A1 (en) | Method and device for fine filtering | |
KR20090042514A (en) | A blow-over prevention structure for a vehicle engine's closed crankcase ventilation | |
KR200223972Y1 (en) | Differential pressure gauge device of suction diffuser and strainer | |
KR100421461B1 (en) | Auto flow and temperature control valve | |
JP2017044218A (en) | Hydraulic pump device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ATLAS COPCO ROCK DRILLS AB, SWEDEN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NYDAHL, ANDERS;REEL/FRAME:028108/0902 Effective date: 20120312 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
AS | Assignment |
Owner name: EPIROC ROCK DRILLS AKTIEBOLAG, SWEDEN Free format text: CHANGE OF NAME;ASSIGNOR:ATLAS COPCO ROCK DRILLS AB;REEL/FRAME:045425/0734 Effective date: 20171128 |
|
CC | Certificate of correction | ||
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20211003 |